Improvement in hot-air furnaces



2 Sheets-eSheet L GEORGE THOMAS. Improvement in Het Ai`r Furnaces.Vl111.`i18,5299. A

Patented Aug 22, 1871.

GEORGE G THoMAs.

Improvement in Hot Air Furnaces. No. 118,299. r .Patented Aug.,22,1871.

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GEORGE G. THOMAS, OF ST. LOUIS, MISSOURI.

IMPROVEMENT IN HOT-AIR FURNACKES.

Specification forming part of Letters Patent No. 118,299, dated August22, 1871.

To all 'whom it may concern:

Be it known that I, GEORGE G. THOMAS, of St. Louis, in the county of St.Louis and State of Missouri, have invented a new and useful Improvementin Furnace; and I do hereby declare that the following is a full andexact description of the same, reference being had to the accomv panyingdrawing and to the letters of reference marked thereon.

This invention relates especially to that class of furnaces which isdesigned for burning soft coal; and consists in certain details ofconstruetion which will be fully described hereinafter.

In the drawing, Figure 1 represents a central sectional elevation of myimproved furnace. Fig. 2 represents two halfsections, the upper beingtaken in the line O D, Fig. 1, and the lower on a line above theash-chamber of the furnace. Fig. 3 represents a side elevation of thelire-brick, and Fig. 4 a plan view of one edge of the same. To enableothers skilled in the art to make and use my invention, I will nowproceed to describe fully its construction and manner of operation.

A represents the base of the furnace, consisting of an inner circularwall, a, constructed of any proper material, which wall incloses theashchamber b, and an outer quadrangular wall, al, inclosing anair-chamber, b', as shown. The wall a is extended out in front to meetthe wall a1, by which means access is obtained tothe ash-chamber throughthe door a2, as shown. C represents a circular ring or plate, setpreferably a little below the upper edge of the wall a, and providedwith an internal ange, c, as shown. This plate is suitably perforated,as indicated in the drawing. D represents the grate, which may be of anysuitable construction, and arranged in any proper manner. E E representseries of rebrick, the lower edges of the lower series of which restupon the plate O, as shown. These brick are peculiarly constructed; theyare deeply grooved or uted upon their outer circumference', with theexception of the upper ring or series, and they arefalso provided withsemicircular depressions upon their adjacent edges. The lower seriesalso is further provided with a iiange or projection, e, upon its inneredge, by which means an open space is left over the openings in theplate C. F represents the radiator which incloses the fire-chamber. Itconsists of a cylinder of any proper material and construction, which isprovided with the usual openings for receiving fuel and discharging theproducts of combustion. G represents a series of open tubes, g g,arranged contiguously about the cylinder F, and fastened thereto bymeans of a band, as shown in Figs. 1 and 2, by which means they are maderemovable at will. H represents the outer cylinder which incloses thehot-air chamber, and is provided with the usual pipes for conveying theheated air to any desired point.

The operation is as follows: Fuel is applied to the fire-chamber in theusual manner, and the products of combustion, as it is consumed, passoff through the smoke-pipe. From the peculiar construction, however, ofthe plate O and the fire-brick air is admitted from the ash-chamber upthrough the lues formed by the grooves in the brick, and through thevarious openings directly into the fire. By this means the consumptionof the gases and smoke of the soft coal are that the smoke and gases ofthe soft coal are very much more perfectly consumed than in the ordinaryfurnace; and also that a very large proA portion of the heat is retainedby the open tubes in the hot-air chamber, while the tubes themselves arenot brought in contact with the products of combustion, and they cannottherefore possibly become lled with soot.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

l. The series of open tubes G, arranged in the hot-air chamber about theradiator F, and held by the securing-band, as described.

2. The fiunace described, consisting ofthe base A, constructed asdescribed, plate O, bricks E, radiator F, removable tubes G G, andcylinder H, the parts being constructed and arranged as described.

GEO. G. THOMAS.

Witnesses H. L. GRosE, W. F. GREENE.

